Elektronika 2009-11.pdf - Instytut Systemów Elektronicznych

• data regarding their identity (details of repairs): their
names, times their threads were started up and finished,
PIDs (Process IDentifiers) of those threads, names of related
scripts, with repair algorithms, binding repairs with
scopes of problems triggering them,
• information on making connections (with particular machines
and as particular users) in the complex topology
network, existing in the enterprise (connection tree).
Case study of exemplary repair
This subsection contains description and repair algorithm of
exemplary problem.
Brief description of the solved problem
The examined problem is databases-related and may be characterized
as follows:
• each change in database is added to journal files (known
also as redo log files),
• once a day, after successful backup of the whole database
(called here checkpoint) is made, journal files are deleted
and their creation starts from scratch again,
• creating and enlarging of the journal files is realized by
a database archiver process,
• lack of space in the filesystem, where those files exist,
stops the database.
Flowchart of the solution
The way this problem is solved has been depicted in the Fig. 2.
Conclusions
The RMS and all other components of the RMF have been
successfully implemented. Formal specifications of the RMM
and the repair library formed the base for further development
and left room for different implementations, sharing the
same idea. The RMS with the prototype repair library (the
repair API) are under tests in the Lufthansa Systems Poland
Company. The API was implemented in the Perl programming
language and the first experiments show that the system
and its API meet the expectations of providing adequate
support to the repair process. Experiments involved mentioned
problem and its repair procedure which was easily implemented
(using routines, derived from formal model), after
representing it by a flowchart.
Further experiments aiming at assessment of the effectiveness
and efficiency of the RMS and benchmarking it with
the traditional approaches are in the planning phase. Among
expected benefits of the proposed approach are increase of
reuse of repair procedures, better reliability of the repair
process, significant increase of performance and better manageability
due to improved documentation. The RMS incorporates
existing monitoring systems and it is noticeable that
repairs became faster, well-documented (so their results can
be included in the internal reporting systems), and that administrators
may focus on more complicated tasks.
References
[1] Škiljan, Z., Radič, B.: Monitoring systems: Concepts and tools.
University Computing Centre, Croatia (2004).
[2] Kamiński, M.: XML-based monitoring and its implementation in
Perl. Proceedings of the 2nd National TPD Conference, Politechnika
Poznańska Press, Poland (2007).
[3] Kamiński, M.: HVRmonitor - data replication monitoring method.
Proceedings of the 2nd AIS SIGSAND European Symposium on
Systems Analysis and Design, University of Gdańsk Press,
Poland (2007).
[4] Barth, W.: Nagios. System and Network Monitoring. O’Reilly
Press, USA (2006).
[5] David, J.: Building a monitoring infrastructure with Nagios. Prentice-Hall,
Great Britain (2007).
[6] Turnbull, J.: Pro Nagios 2.0, Apress, USA (2006).
[7] Zabbix reference manual: http://www.zabbix.com/documentation.php.
[8] Zanikolas, S., Sakellariou, R.: A taxonomy of grid monitoring systems.
School of Computer Science. The University of Manchester,
Great Britain (2004).
[9] Ceccanti, A., Panzieri, F.: Content-Based Monitoring in Grid Environments.
Proceedings of the 13th IEEE International Workshops
on Enabling Technologies. Department of Computer
Science, University of Bologna, Italy (2004).
[10] Jianwei, L., Hongbin, C., Pandeng, J., Meirong, C.: Design and
Implementation of Grid Monitoring System Based on GMA. Proceedings
of the 6th IEEE International Conference on Parallel
and Distributed Computing. Applications and Technologies College
of Computer Science, and University of Electronic Science
and Technology. China (2006).
[11] Cooke, A., Nutt, W., Magowan, J., Taylor, P., Leake, J., Byrom,
R., Field, L., Hicks, S., Soni, M., Wilson, A., Cordenonsi, R.,
Cornwall, L., Djaoui, A., Fisher, S., Podhorszki, N., Coghlan, B.,
Kenny, S., O’Callaghan, D., Ryan, J.: Relational Grid Monitoring
Architecture (R-GMA), Joint article published in GridPP. University
of London, Great Britain (2003).
[12] Campi, N., Bauer, K.: Automating Linux and Unix System Administration.
Apress. USA (2009).
[13] Strejcek, B.: Automate admin tasks with the powerful CFengine
framework: http://www.linuxpromagazine.com/issues/2009/
101/big_engine.
[14] Gerlan, D., Schmerl, B.: Model-based Adaptation for Self-Healing
Systems. School of Computer Science, Carnegie Mellon University,
USA (2002).
[15] Gerlan, D., Shang-Wen, C., Schmerl, B.: Increasing System Dependability
through Architecture-based Self-repair, School of
Computer Science, Carnegie Mellon University, USA (2003).
[16] Gerlan, D., Shang-Wen, C., Schmerl, B., Sousa, J. P., Spitznagel,
B., Steenkiste, P.: Using Architectural Style as a Basis for
System Self-repair, School of Computer Science. Carnegie Mellon
University, USA (2002).
[17] Retkowski, G.: Building a Self-Healing Network: http://www.onlamp.com/pub/a/onlamp/2006/05/25/self-healing-networks.html.
[18] Pervilä, M.: Using Nagios to monitor faults in a self-healing environment,
Department of Computer Science, Helsinki University,
Finland (2007).
[19] Woodcock, J., Davies, J.: Using Z.: Specification, Refinement,
and Proof, University of Oxford, Great Britain (1999).
[20] Potter, B., Sinclair, J., Till, D.: An Introduction to Formal Specification
and Z, International series in computer science, Prentice-
Hall. Great Britain (1991).
[21] Spivey, J.M.: The Z notation - A Reference Manual, Prentice-
Hall. Great Britain (1992).
[22] Kamiński, M.: Towards automating repairs of IT systems, article
accepted (basing on its abstract) and submitted to the 30th International
ISAT Conference (Information Systems., Architecture,
and Technology). Poland (2009): http://www.isat.pwr.wroc.pl/.
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